Look for outboard wheels rather than ones under the cart. Not as narrow, but less tippy.

You want the center of gravity as low as you can go.

If it’s a paved slope you can use something with small wheels.

That’s part of the reason I bought a hand truck – it seemed much more controllable on the driveway.

I have a family member who was gifted one of these by a neighbor who moved. I was asked to help fix it up and one of the first things I did was generously fill each tire with “slime” type sealant. That lasted about 4 years before two of the tires started disintegrating. Now it has run-flats on it, I paid $49.99 for a set of 4 from Amazon last year. Currently they’re showing at $55 for the set.

The “hauling cart” I use for heavy stuff is the harbor freight lift cart. It might not be the best for soil/garden work, but it’s great to have an adjustable height available easily.

For soils and such maybe I should add off-road wheels to this shopping cart I got at an auction for $5.

They also have a 48×24 metal deck wagon (https://www.amazon.com/Farm-Tuff-Metal-24-Inch-48-Inch/dp/B0000AX6MG/?tag=toolguyd-20), as well as 40×20 plastic deck wagon with similar frame as the plastic cart.

There are also different versions of most, with flat free wheels instead of pneumatic.

Home Depot has the same thing for the some price plus a heavier duty one (1,200 lbs) for $193.

Pro Tip: Cut a piece of 3/4″ plywood to fit snugly in the bottom and keep the air compressor handy – all these have pneumatic tires. Run-flats would be better, but you would have to buy them yourself and install them (Home Depot sells a set for $59, didn’t see anything at Lowes.. AFAIK, there’s no trade-in value for the pneumatics)

I’ve got one of the 48X24 1,000 lb ones I bought at Lowes 15 years ago for $69, and it – with the plywood floor – will do things no other cart will. It’s hauled fertilizer, topsoil, concrete blocks, 5 gallon water jugs, paint buckets, lumber (let 4 ft hang off the back and hold the front 4 feet down with a ratchet strap), you name it. The only thing I’d like for it to have is a dump bed and run-flats.

Collapsible carts are useful, but the intended uses, build quality, and load capacity are completely different.

I use my plastic-deck cart to haul gardening supplies, such as bulk packages of compressed potting soil, bags of mulch, and the like.

I was looking at a flat platform for hauling equipment around, but ultimately a convertible hand cart has a smaller storage footprint.